How are interlocking limits defined in railway terminology?

Interlocking limits are defined as the tracks between outer opposing absolute signals of interlocking. This is a crucial concept in railway operations as it pertains to the control and safety of train movements within a designated area. The outer opposing absolute signals represent the boundaries of the interlocking, ensuring that trains can only enter the interlocking limits when it is safe to do so. This area is typically controlled by a signal system that governs the movement of trains, allowing for proper coordination to prevent collisions and ensure safe passage through junctions and crossings.

In contrast, the other options do not accurately capture the definition of interlocking limits. The notion of interlocking being related to the area between any two stations does not apply since interlocking limits are concerned specifically with signal control rather than the distance between stations. Identifying a length of track designated for maintenance or the distance between two set points on a route also lacks relevance to the specific function and operational control inherent in interlocking limits. Thus, the correct definition focuses on the safety mechanisms provided by the signals that govern train movements within those bounds.